there is a few folder “citra” which one I have to copy?
there are 2 folder “user” in “roaming”: C:\Users\Francesco\AppData\Roaming\Citra\nand\data\00000000000000000000000000000000\extdata\00000000\F000000B\user
And
C:\Users\Francesco\AppData\Roaming\Citra\nand\data\00000000000000000000000000000000\extdata\00048000\F000000B\user
(With inside 1 file: gamecoin.data)

This folder C:\Users\Francesco\AppData\Roaming\Citra is the user folder . Within in it there will be config, nand, log, sdmc, etc folders. Copy these folders to a new folder and name it user and move it to the CItra directory (the one with citra-qt.exe) that you want to run in portable mode.

In this example, I’ll use C1tra and Ci2ra as a way of distinguishing the Citra versions.
Okay, you need to…
Copy your entire C1tra folder somewhere easy to remember, make a folder INSIDE OF SAID FOLDER, and NAME IT user. (This is now Ci2ra)
Go to C:\Users%username%\AppData\Roaming\citra\ and copy it all, putting it into Ci2ra’s user folder.
Open the Ci2ra program, go to Emulation, then click Configure, then click System, and in System, click Regenerate your Console ID, and give it a di…

right click on your game on citra game list and select ‘Open Save Data Location’,
your savedata is in a folder structure that goes up to folder 00040000,
e.g: 00040000\001b5000\data\00000001. the whole folder 001b5000 (in this example) is your save game.

each folder inside 00040000 is a save game for a different game (just to make things clear)